1. Field of the Invention
The present invention relates to methods, apparatus and computer-code for acquiring and presenting information related to database performance.
2. Background and Related Art
It is common for large or “heavy” database tables or indexes to be partitioned into multiple “table partitions” or “index partitions.” During statement tuning, users (i.e. DBAs) need to identify how many partitions were accessed, and which partitions were accessed by the statement. This may affect statement response time dramatically.
Unfortunately, may be difficult to track I/O wait time by table or index partition identity because: (i) for many statements (i.e. the overwhelming the majority of statements in many applications), it is difficult to determine how many or which partitions were accessed during execution of a given statement (i.e. for most statements, this information is not available from the SQL statement execution plan generated by the query optimizer); (ii) even if it were known which partitions were accessed, it would be difficult to determine the relative wait-time contributions of each partition when accessing a given table or index.
Thus, there is an ongoing need for a tool which can track table or index partition access. Furthermore, it would be possible provide a number of database tuning applications using the aforementioned currently-unavailable functionality for tracking I/O wait time by table or index partition identity. These tuning applications are discussed below.